(1) Field of the Invention
The present invention relates to a method and apparatus to automatically and electronically read in bar codes, each of which is recorded with a plural numbers of bar symbols of different width on a surface of an object.
(2) Description of the Prior Art
Information encoding and decoding techniques are well known in the art. One of these prior art techniques is shown in FIG. 1 schematically. In the shown art, numbers of bar symbols 80b of different bar width and light reflectivity are printed in parallel with each other on a card 80 to represent information. A pen-type reader A, electrically coupled to a signal processing unit B, is manually actuated to slide over and scan the bar symbols 80b in a direction orthogonal thereto. The reader A is light-responsive and electrical signals corresponding to the bar width and the light reflectivity are derived from the reader A and processed to be read in the unit B thereafter. Since the manual reader scanning speed is apt to change, the read-in accuracy does not suffice for practical use. Further to avoid reading error, one must avoid scanning over the smeared part of the symbols, which necessitates considerable experience and skill.